2008-12-04_PERMIT FILE - C1994082A (14)

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and stop signs have been placed on both sides of the haul road at any intersection. These approaches • are similar to those constructed along the tie-across haul road. The southern portion of the haul road (Road BI is located within steep to near vertical sided canyons with occasional massive sandstone bedrock outcrops.' Haul Roads A and B are designed with appropriate ditches, grades, and culverts to control erosion and runoff. Exhibit 13-9, Typical Haul Road Details and Figures 13-1, Typical Road Embankment and 13-2, Typical Road Cut, illustrates typical cut and fill sections of the haul roads. The proposed haul roads were designated as Haul Road B Extension, Haul Road C and Haul Road D. The proposed locations of these roads are shown on Exhibit 12-1, Operations Plan, while the designs for each proposed road are presented on Exhibit 73-11,3, Proposed Haul Road B Extension; and Exhibit 13-11.4, Proposed Haul Roads C and D. The majority of these proposed haul roads were built prior to the time mining commences. However, some of the haul roads were extended through the spoil and road construction progressed along with the mining activity. Final reclamation of these roads will occur as the areas are mined out or as the roads are no longer needed. The haul roads were designed for the anticipated volume, weight and speeds of vehicles to be used. The proposed haul roads will be constructed in the same manner that the existing haul roads were constructed. The haul road width, curves, and base material are consistent with the existing haul roads and ramps. SCC has been hauling coal over the existing haul roads for over two years without • any operational problems. SCC doesn't anticipate changing hauling equipment during the remaining life-of-mine; therefore it is SCC's opinion that the proposed designs are adequate to handle the anticipated traffic load. Haul roads are located, to the extent possible, on ridges or along the most stable available slopes to minimize erosion. In the unlikely case that a haul road must be routed across a portion of an unconsolidated surficial landslide, SCC either removes the surficial, slide material or conducts a geotechnical investigation to determine the characteristics and extent of any possible instability. This circumstance is identified in the field prior to actual construction and a qualified engineer determines if any changes in construction methods or design are required. Haul Road D contained sections steeper than 10 percent and at the request of the Division a stability analysis was performed for the associated cut and fill slope. The stability analysis indicates a static factor of safety of 2.1 for the fill slopes and 2.6 for the cut slopes. The results are included in Attachment 13-16, Haul Road D Stability Analysis. The area of proposed Haul Road "B" Extension was mapped as Qols -Quaternary unconsolidated older surficial landslide deposits, from aerial photos (see Exhibit 6-1, Site Specific Geology, and Exhibit 12- 1, Operations Plan, for locationsl• Based on this mapping and physical investigations/observations, the mapped surficial materials appear to have already slid and are now in a stable configuration, otherwise • there would be evidence of recent movement. SCC removed and stockpiled the topsoil from this area in the Fall of 1998, thereby unloading and removing any potentially unstable material remaining, and has not observed any signs of further instability to date. A physical investigation of the disturbed areas was conducted in May of 1999 and no indication of movement or instability was observed PR-02 12 Revised 03/05